1. Technical Field
The present technology relates to a toner cartridge enabling use while avoiding coagulation of the toner, and an image forming apparatus.
2. Description of the Related Art
The image forming apparatus such as copying machine and printer adopting an electrophotographic method includes a photosensitive drum, a toner cartridge removably attached to the image forming apparatus, and a developing unit.
When the image forming apparatus forms the image, an electrostatic latent image corresponding to an image to be formed (hereinafter referred to as image to be reproduced) on a recording sheet such as recording paper and OHP sheet is formed on the surface of the photosensitive drum. The toner cartridge supplies developer (specifically, toner) or colorant to the developing unit, and the developing unit makes the toner adhere to the electrostatic latent image formed on the surface of the photosensitive drum to develop the toner image (i.e., develop the photosensitive drum).
Such image forming apparatus irradiates light to the surface of the photosensitive drum to form the electrostatic latent image corresponding to the image to be reproduced after evenly charging the surface of the photosensitive drum. The electrification charges of the region irradiated with light at the surface of the photosensitive drum are removed, where non-removed portion becomes the electrostatic latent image. The toner is then supplied to the surface of the photosensitive drum to be adhered to the charged region (i.e., electrostatic latent image) of the surface of the photosensitive drum, and the toner image corresponding to the image to be reproduced is developed on the surface of the photosensitive drum. Finally, the image to be reproduced is formed on the recording sheet by transferring the developed toner image onto the recording sheet.
The toner in the toner cartridge is consumed as the toner cartridge supplies toner to the developing unit. High quality images become difficult to form if the amount of toner supplied from the developing unit to the photosensitive drum is insufficient, and thus the image forming apparatus detects the remaining amount of toner contained in the toner cartridge, and informs the user, the manager and the like (hereinafter referred to as worker) of the image forming apparatus when the toner is insufficient that it is time to change the toner cartridge etc. The worker who recognizes the timing to change the toner cartridge detaches the toner cartridge attached to the image forming apparatus, and attaches a new toner cartridge to the image forming apparatus. That is, an empty toner cartridge is replaced with a new toner cartridge so that toner can be replenished to the image forming apparatus.
An image forming apparatus equipped with a toner replenishing device to maintain the toner amount in the developing unit constant is also known. In such image forming apparatus, when insufficiency of toner is detected, the toner is automatically replenishing by the toner replenishing device in response to the detection. The toner amount in the developing unit is thus maintained constant, and a constant image quality is always maintained. The toner cartridge for replenishing the toner to the toner replenishing device is also used in the image forming apparatus equipped with the toner replenishing device. In this case, the worker attaches the toner cartridge to the toner replenishing device, replenishes the new toner contained in the toner cartridge to the toner container of the toner replenishing device, and detaches the toner cartridge from the toner replenishing device after replenishing is completed.
The toner is in a form of microscopic powder and has fluidity close to liquid, but if the toner cartridge is left untouched for a long period of time, the toner in the toner cartridge coagulates, whereby the fluidity lowers and a behavior close to a solid is exhibited. The toner having sufficient fluidity can be easily supplied to the developing unit, and furthermore, to the photosensitive drum, but the coagulated toner tends to retain in the toner cartridge as the fluidity is low, and becomes difficult to be supplied to the developing unit and the photosensitive drum. As a result, a drawback in that toner is insufficient at the photosensitive drum although sufficient amount of toner exists in the toner cartridge arises.
In order to prevent such drawback, the worker needs to sufficiently dissolve the toner by shaking the toner cartridge and stirring the toner in the toner cartridge before attaching the toner cartridge to the image forming apparatus. However, such shaking of the toner cartridge is manually performed by the worker, and thus some workers might attach the toner cartridge to the image forming apparatus without shaking the toner cartridge until the toner is sufficiently stirred and dissolved.
Conventionally, a toner cartridge incorporating a toner stirring member is proposed such that the toner is sufficiently stirred and dissolved even if the number of times the worker has shaken the toner cartridge is few (see e.g., Japanese Patent Application Laid Open No. 10-288882).
However, the necessity itself to shake the toner cartridge is not acknowledged by the worker, and the worker might attach the toner cartridge to the image forming apparatus without shaking. In this case, the toner is barely stirred and dissolved even if the toner cartridge disclosed in Japanese Patent Application Laid Open No. 10-288882 is used.
Even if the worker shakes the toner cartridge, the toner will not be sufficiently stirred and dissolved if the number of times the worker has shaken the toner cartridge is less than the requisite minimum number of times to shake to sufficiently stir and dissolve the toner.
Furthermore, even if the user is aware of the requisite minimum number of times to shake the toner cartridge, it is troublesome for the worker to count the number of times the worker has shaken the toner cartridge, whereby counting mistake, loss of counting result etc. may occur and the number of shaking movements may insufficient.